Chevy's C7 Z06 LT4 supercharged V8 heat soak and overheating problem

[Sticky]

The C7 Corvette Z06 definitely has an engine cooling problem. We have speculated for some time about this due to inconsistent Z06 performance. GM even advised owners to get an aftermarket tune to combat timing being pulled due to heat soak.

The relatively small R1740 TVS is obviously being spun harder than the previous generation C6 ZR1's 2.3 liter blower used on the LS9. The benefit of the smaller blower is quicker response from the lighter rotors but the higher rpm generates more heat it seems.

You can obviously surmise how this would be a problem at the track when attempting repeated laps as the Z06 is supposed to be a track car. However, the C7 Z06 overheated on MotorTrend during a summer freeway cruise.

That's kind of a problem. A big one.

OK Chevy, you've got a problem. This just happened to the Z06 after a 45-mile freeway cruise. We're talking 70-85 mph at about 6:00 pm. Hot, but not crazy hot. 80-85 F. The weird part is the as you can see from the temp gauge, the coolant temp is fine. What then is overheating? And why? #Chevrolet #Corvette #Z06 #BigNasty #overheat #LT4

A photo posted by Earth's Automotive Authority (@motortrend) on Aug 2, 2015 at 7:05pm PDT

[Stevenh]

Its about time a big name calls them out on this. I'd love to see an official response. I'm curious if owners would have grounds for a class action lawsuit similar to the early 2000 era Cobra owners.

[ezec63]

Its about time a big name calls them out on this. I'd love to see an official response. I'm curious if owners would have grounds for a class action lawsuit similar to the early 2000 era Cobra owners.

They posted later on about what happened. The water pump broke causing the engine to over heat I think its obvious this car is not going to over heat cruising on the highway even if its cooling system isn't the greatest.

[JerryT]

Yikes!

[Sticky]

They posted later on about what happened. The water pump broke causing the engine to over heat I think its obvious this car is not going to over heat cruising on the highway even if its cooling system isn't the greatest.

That makes a hell of a lot more sense. Glad they followed up.

The car definitely still has some cooling issues though.

[leveraged sellout]

The fact that the water pump broke isn't confidence inspiring either. A couple of these have blown up on a dyno already, bottom end let go. They have some serious issues to work out, really hope the CTS-V doesn't have the same problems...

[Sticky]

The fact that the water pump broke isn't confidence inspiring either. A couple of these have blown up on a dyno already, bottom end let go. They have some serious issues to work out, really hope the CTS-V doesn't have the same problems...

Whose bottom end gave out and at what level/why?

Saw a CTS-V yesterday. It looks nice and fairly muscular. The Germans still looks more refined though at least from the exterior.

[leveraged sellout]

Whose bottom end gave out and at what level/why?

Saw a CTS-V yesterday. It looks nice and fairly muscular. The Germans still looks more refined though at least from the exterior.

Someone on Jalopnik who knows a guy who runs a shop is talking about it in the comments here http://carbuying.jalopnik.com/chevro...ter-1724296112

I've heard whispers about this on the car forums but this seems more concrete. Sorry about their $#@! commenting system, you'll have to find it, but there's not many comments yet so might be quick.

[E90Company]

The ZR1 didn't have this problem. It's GM's fault they put a tiny blower on their new motor what did they think was going to happen? You can't spin that baby blower to the moon and expect to make more power than the LS9 with the same cooling.

[Sticky]

Someone on Jalopnik who knows a guy who runs a shop is talking about it in the comments here http://carbuying.jalopnik.com/chevro...ter-1724296112

I've heard whispers about this on the car forums but this seems more concrete. Sorry about their $#@! commenting system, you'll have to find it, but there's not many comments yet so might be quick.

I don't understand why these big blogs use such garbage commenting systems but it's fine with me.

The LT4 seems to have some issues whether people want to admit it or not.

[Sticky]

The ZR1 didn't have this problem. It's GM's fault they put a tiny blower on their new motor what did they think was going to happen? You can't spin that baby blower to the moon and expect to make more power than the LS9 with the same cooling.

It does make more power and torque though. That power doesn't seem to show up in races or on the dragstrip though.

It also doesn't seem to stay and quickly gets heat soaked.

I don't understand the GM engineers here. They know better.

[leveraged sellout]

I don't understand why these big blogs use such garbage commenting systems but it's fine with me.

The LT4 seems to have some issues whether people want to admit it or not.

Kinja is literally an abomination. I have no idea how they chose it, must have been money involved.

Yeah it's really upsetting that they seemed to have 90% of a great engine...but messed up some key points and now it's a potential liability. Rumors are that the CTS-V production is being held up a bit because of last minute changes to the engine to prevent problems but that might be wishful thinking.

[Zombie1]

Wow spend all that money to have a "track" cart at overheats on a summer night while cruising that's just unacceptable.